Survival of Aerosolized SARS-CoV-2 on Masks

JIN PAN, Aaron Prussin II, Seth Hawks, Nisha Duggal, Linsey Marr, Virginia Tech

     Abstract Number: 27
     Working Group: Aerosol Science of Infectious Diseases: What We Have Learned and Still Need to Know about Transmission, Prevention, and the One Health Concept

Abstract
The potential for masks to act as fomites in the transmission of SARS-CoV-2 in real-world situations is not well understood. In theory, a person could touch a contaminated mask and transfer virus to their mucus membranes, but for infection to occur, the virus must maintain infectivity while on the mask, among other steps in the process. Several studies have evaluated the persistence of SARS-CoV-2 on different types of masks, but the methods relied on inoculating the surface with unrealistically large droplets containing the virus. Under such conditions, survival of SARS-CoV-2 may be prolonged, and hence the potential for fomite transmission may be exaggerated. In this study, we contaminated the masks in a more realistic way: we aerosolized a suspension of SARS-CoV-2 in saliva at a realistic titer and used a vacuum pump to pull the aerosol through six different types of masks. SARS-CoV-2 lost all detectable infectivity within an hour at 28°C, 80% RH on an N95, surgical mask, polyester mask, and two different cotton masks. The virus was still viable on a nylon/spandex mask. SARS-CoV-2 RNA remained stable for an hour on most of the masks. Differences in particle collection efficiency and elution efficiency among the masks influenced the results. The potential for masks contaminated with SARS-CoV-2 aerosols to act as fomites appears to be less than indicated by studies involving inocula with very large droplets.